Microarray fabrication: Which manufacturing technologies are used to create high-density microarrays for genomics and proteomics?
-
APhotolithography (in situ synthesis via light-directed chemistry)
-
BInk-jet deposition (non-contact spotting/printing)
-
CContact printing (pin-based spotting of probes)
-
DAll of these
-
EHand pipetting of single spots only
Answer
Correct Answer: All of these
Explanation
Introduction / Context:Microarrays place thousands to millions of probes on small substrates for parallel biological measurements. Multiple engineering routes exist to pattern probes with positional precision and adequate feature density.
Given Data / Assumptions:
- Candidate technologies: photolithography, ink-jet deposition, and contact printing.
- Goal is to immobilize oligonucleotides or biomolecules at defined coordinates.
- All three methods are widely cited in microarray literature.
Concept / Approach:Photolithography enables in situ probe synthesis using light-directed deprotection across a mask or micro-mirror system. Ink-jetting delivers small droplets to defined spots. Contact printing uses pins to transfer probe solutions to surfaces. Each has advantages in feature size, flexibility, and cost.
Step-by-Step Solution:
List known fabrication approaches and their roles.Confirm each achieves ordered placement of probes on a substrate.Conclude that all three are valid and widely used.Verification / Alternative check:Commercial platforms and academic labs employ all three strategies, with trade-offs in density, uniformity, and customization throughput.
Why Other Options Are Wrong:
Hand pipetting of single spots only: not practical for dense, reproducible arrays.Common Pitfalls:Assuming only one “standard” method exists; in practice, platform choice depends on application and cost.
Final Answer:All of these.